Calculeaza cantitatea de solutie de clorura de sodiu cu concentratia 30% necesara pentru obtinerea a 112 L de clor (c. n). Ce volum de hidrogen se obtine la catod?

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)